Interlock



May 20, 1941. D. J. DE'rRlcl-l 2,242,238

INTERLOCK Filed Dec. 8, l193s ATTORNEY y' Patented May 20, 1941 INTER/LOCK vDonald J. Detrch, Columbus, Ohio, assignor tov The Steel Storage File Company, Cleveland, Ohio, a corporation `of Ohio Application December 8, `1938, SerialvNo. 244,601

(Cl. 18S-436) 3 Claims.

The present invention relates to mechanical interlocks which can be readily applied to or removed fromthe elements to be attached.

One of the objects of the present invention is to provide an interlock for two elements, such as sheet material of any type, comprising a projecting part formed on one element that is adapted to extend through an opening in the other element, the projecting part having a shoulder and an opening through which the leg of a key is extended for preventing removal of the projecting part from its opening, the end of the leg of the key extending through the opening being supported'by a part of one of the elements to prevent flexing of the leg relative to the projecting part, and the key having a section adapted to extend alongside the projecting part and having a shoulder arranged to abut the shoulder on the projecting part to prevent accidental removal of the key.

Another object is to form the key of flexible and resilient material so that the leg and the section can be flexed, relative to one another, when the key is being attached or removed.

` Another object is to utilize the key asa camming device for the purpose of forcing the elements which are to be interlocked, toward one another.

It is a further object of the invention to insert a leg of the key through the opening in the projecting part of one of the sheets to be interlocked, the ends of the'leg frictionally engaging the other of the sheets' to be interlocked and then utilize the leg as a cam for forcing the sheets toward oneanother.

Other and further objects and advantages will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawing:

Fig. `1 is a plan View of one of the elements to be interlocked;

Fig. 2 is a plan View of the other element;

Fig. 3 is a plan view of the key for inter-v .l

locking the elements shown in Figs. 1 and 2;

Fig. 4 is a plan view of the elements shown in Figs. 1 and 2; the element shown in Fig. 11

resting on the element shown in Fig. 2, and,

`showing the key about to beapplied to interlock the elements;

Fig. 5 is a plan view showing the key and elements in interlocked position; and,

Fig. 6 is a, sectional view taken on line 6-6 of Fig. 5.

Referring to the drawing, for the purpose of illustrating one embodiment of my invention, I have Vvselected twol `sheets of material which are to be interlocked. These sheets may be of any shape or iconguration, for example, the confronting faces may be arcuate and if so, the

`interlocking key may be shaped to conform to the shape ofthe confronting faces. However, to simplify the illustration, I have selected two flat sheets. These sheets are more or less rigid and may be of sheet metal, molded material such as Bakelite, molded ber board, etc. One of these sheets is shown at 21 andthe other at 28. Sheet 21 is provided with an opening 4I which is arranged to receive a bulged portion or locking member 42 on sheet v28. The opening 4I `conforms substantially in width and length with that of bulged portion v42. If sheet 28 is metal,

V.the bulged portion would be formed by a drawing operation to form a recess 43 on the underside thereof; also the sheet would be pierced or in any way suitable cut to form openings 44 and.

4l) tothe recess 43 on the underside thereof to form an ropening through thebulged portion to receive a key which will herein after be described. The side of the portion 42 which is pierced to form the opening 40 also forms a shoulder 45 and the underside forms an abutment 46.

When the sheets 21 and 28 are superimposed, the Atop part of portion 42 projects through the opening 4| in sheet 21 so that partof each opening 44 and 40 is above the top of sheet 21. rPhe sheets 21 and 28 are interlocked by a key 41. This key is formed of flexible and resilient material, for example, it may be a stamping of sheet metal. Key 41 includes a key 48 which merges into a yoke section 49.

The free end of leg 48 includes tongue 54 formed integrally therewith. Leg sections 5U, formed integrally with the yoke section 49 are disposed on opposite sides of the leg 4B. These legsectionseach include a portion 52 forming a shoulder 53 facing the free end of the leg 48.

If desirable only vone of these legis 5i) need be employed, however in the preferred embodiment shown I utilize twosuch legs and these legs may be joined with one another adjacent the free end of the leg 50 if desired. The leg 48 is provided with a ridge 5| which starts rearwardly of the `tongues 54 and slopes upwardly, gradually. The ridge 5I will hereinafter be referred to as acam.

In the attached position, leg 43 projects through the opening 44 and the tongue portion 54 extends through the opening 40 in the wall opposite the opening 44 in locking member 42 and yoke 49 and legs 5B substantially surround the projecting part of member 42. The shoulders 53 onlegs 50 are arranged to engage shoulder 45 on the locking member 42 to prevent accidental removal of the key from its locking position. The cam 5| frictionally -engages the vabutment v.46 and legs 5U frictionally engage the position shown in Fig. 4 in which the portion 52 of the legs 50 overlap the edge of member 42 adjacent the opening 44. The leg 48 is depressed to align the same with the opening 44. Simultaneously, it is pulled forwardly so that the tongue 54 will enter the opening 44. Upon further forward movementI of the key, the tongue 54 of the leg 48 will pass through the opening 40 and extend above the top surface of the member 21. The forward end of the tongue 54 may be beveled or bent slightly upwardly to prevent the tongue from catching on the sheet 21 as it is moved over the sheet. Before the key 41 reaches the locking position shown in Figs. 5 and 6 the cam` 5i will engage the abutment 46 of the locking member and as the key is moved to the locking position, the members to be interlocked will be forced toward one another. Obviously leg sections 50 must be flexed relative to leg section 43 when the key is being attached because the portions 52 of the legs 50 must pass over the top of the member 42, however, the material of the key is resilient and after the portions 52 are pulled lbeyond the shoulder 45, they will lie flat upon the sheet 21 with their shoulders 53 in abutting relation with shoulder 45.

The tongue 54 of the leg 48 can readily be inserted into the opening 44 of member 42 although the opening extends only a short distance above sheet 21. The cam 5l slopes upwardly gradually and therefore forces the sheets 21 and 28 toward one another. As the key is moved toward locking position after it has been inserted through the openings 44 and 48 the cam bears upon the abutment 46 and the tongue and opposite end of the leg bear upon the sheet 21 to force the sheets into binding relation with one another. Thus it is apparent that the key 41 can be readily attached although the confronting surfaces of the sheets are bent or warped, for example, the material of sheet 28 may be bent downwardly or the material of sheet 21 may be bent upwardly about the opening 41 and, in either event the tongue can be readily l,

inserted into the opening 44 and the confronting The material from which the key is formed is sufficiently flexible so that the portions 52 of the legs 58 can be lifted either by ones finger or by a small tool, and in order to unlock the sheets, it is necessary only to lift upwardly on the portions 52 and push rearwardly on the key.

From the foregoing it will be seen that I have provided an interlock which is inexpensive to manufacture, which also functions to cam the elements toward one another, and constructed so that the locking keyitself is in latched position when the key is in interlocking position and provides a positive engagement of the interlocked material adjacent the interlocking means.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

I claim: v

1. In combination, an element having an opening therethrough; a wall formed of sheet material and having a bulged portion extending through the opening, said bulged portion having an opening in each of two opposite end Walls thereof and a shoulder adjacent one of the last mentioned openings; and a locking key formed of sheet material and including a yoke, a leg extending from the yoke and through both openings in the bulged portion, the extending end of the leg frlctionally engaging the element, and aA section extending directly from the same side of the yoke and alongside the bulged portion and engaging said element, said section having a shoulder abutting the first mentioned shoulder when the key is in position, said section being flexible with respect to the leg so that the portion of the section having the shoulder can be raised above the bulged portion when the key is inserted and removed from locking position, said yoke, leg and section being disposed in substantially the same plane.

2. In combination, an element having an opening therethrough; a wall formed of sheet material and having a bulged portion extending through the opening, said bulged portion having an opening in each of two opposite end walls thereof and a shoulder adjacent one of the last mentioned openings, a wall of the bulged portion intermediate the two openings in the bulged portion forming an abutment facing the element; and a locking key formed of sheet material and including a yoke, a leg extending from the yoke and through both openings in the bulged portion, the extending end of the leg frictionally engaging the element, and a section extending directly from the same side of the yoke and alongside the bulged portion and engaging said element, said section having a shoulder abutting the iii-st mentioned shoulder when the key is in position, said section being flexible with respect to the leg so that the portion of the section having the shoulder can be raised above the bulged portion when the key is inserted and removed from locking position, said yoke, leg and section being disposed in substantially the same plane, and a ridge formed on said leg, said ridge extending from the yoke and terminating short of the extended end of the leg.

3. In combination, two walls disposed in side to side relation, one of said walls having an opening therethrough; means forming a shoulder adjacent the opening, said shoulder extending outwardly with respect to said one wall, and a bulged portion extending through said opening and outwardly with respect to said one wall, said bulged portion being connected with the other of said walls and cooperating with opposite edges of said opening for forming a key passage, said shoulder being disposed adjacent one end of said passage; and a locking key formed of sheet material and including a yoke, a leg extending from the yoke and through said passage and frictionally engaging said one wall adjacent said opposite edges of said opening, and a section extending from the same side of the yoke and alongside the bulged portion and engaging said one wall, said section having a shoulder abutting the first mentioned shoulder when the leg is in said passage and urged in a direction to Withdraw the leg from the passage, said section being exible with respect to the leg so that the portion of the section having the shoulder can be raised above the first mentioned shoulder and the bulged portion when the key is inserted and removed from locking position, said yoke, leg and section being disposed in substantially the same plane.

i DONALD J. DE'I'RICH. 

